Producing resinous bases prom tar



UNITED sTATEs PATENT oEEIcE.

ERNST WIRTH, OF DORTMUND, GERMANY, ASSIGNOR, BY MESNE ASSIGNMENTS, TO THE CHEMICAL FOUNDATION. INC., A CORPORATION OF DELAWARE.

PRODUCING RESINOUS BASES FROM TAR.

Specification of Letters Yatent.

Patented May 4, 1920.-

No Drawing. Application filed May 20, 1916, Serial No. 99,254. Renewed August 6, 1919. Serial No. 315,785.

To all whom it may concern:

Be it known that I, ERNST WIRTH, manufacturer, a subject of the German Emperor, and residing at Dortmund, in the German Empire, have invented certain new and 'useful Improvements in Producing Resinous Bases from specification.

The present invention relates to a process for producing from mineral coal tar and other tars, hitherto unknown resinous bases with a high boiling point. Heretofore only acridine had been found in mineral coal tar as a base boiling above 300 cent. and the existence of other bases with high boiling temperatures was unknown. I have now found that there exist further bases, about 3%, with high boiling temperatures both in mineral coal tar and in tar oils with a high boiling point, which bases can, however, not be obtained by a simple treatment with acids, as their salts form insoluble compounds with phenol, its higher homologues and naphthols and other tar components, which compounds make up the greater portion of the acid-tar produced by. the acid treatment of the tar. If, however, the phenols are previously removedfrom the tar or the tar oils, for example by treatment with alkalis, the bases may, to the greater part, be removed directly by aid of acids, while a small part forms with unknown tar components a resinous material, from which the salts of the bases may be removed by boilin in water. From the solution of the salts t e bases may be precipitated in form of a viscid mass by aid of a suitable lye. The bases commence to boil at about 320 cent. whereas the last components pass over in cacao only at more than 400 cent. By fractional distillation in cacao they may thereupon be separated. The components of a low boiling point may be separated in the same manner from the tar oils boiling above 300 cent, the components with a higher boiling point from the pitch remain ing from the distillation of coal tar. The lower fractions are yellow oils, the medium "ones viscid, and the fractions with the highest boiling temperatures solid reddish brown substances. Neither the bases nor their Tar, of which the following is a from tar products and tar oils besides acridine probably of naphthoi-- soquinolins which were unknown heretofore. These bases may be used for manufacturing pharmaceutical products and in the dyestuff industries; the components of the highest boiling point, probably anthraisoquinolins and similar bases, will directly dye wool and silk from a yellow to a brownish red color.

In order to obtain the said bases from the coal tar the following method is preferably employed: 100 kilos of tar is freed of the most valuable components as benzene, its homologues, phenol and pyridin, and, if it is too viscid for filtration, is diluted with about 50 kilos of. a coal tar oil which has been previously freed of phenols and bases. The tar is then freed from the free carbon contained therein by settling or filtration and treated in a mixer at a suitable temperature with caustic soda solution of a specificgravity of 1.15 in such a quantity that all phenols are dissolved, as for instance, 10 liters. After settling, the soda lye containing the phenols is drawn off and the remaining tar is well stirred with 10 liters of dilutesurfuric acid of a specific gravity of 1.12. When settled, the aqueous solution containing the sulfates of the new bases is drawn off at the bottom. After cooling, the coal tar purified by this treatment can be sepaolin and its homologues, boiling at 236 to about 290 cent. At 320 C. the new bases begin to come over together wtih the acridine which may be separated by repeated fractional distillations.

In the same manner the bases can be extracted from the heavy coal tar oils boiling above 300 cent. and also from coal tar pitch, which must be diluted with a larger quantity of light coal tar oil.

The tar freed from these bases consists of a viscid dark' brown oil which even when highly heated will not be decomposed or form coke, and which is therefore excellently suited for heating and also as a lubricant.

I- claim:

1. Process of recovering resinous bases having a high boiling point from tar, consisting in distilling off the phenols, diluting it with coal tar, previously freed of phenols, remov ing the carbon by filtration, treating the product with a caustic soda solution, removing the soda lye, stirring the product with diluted sulfuric acid, removing the sulfates, cooling the mass, and separating thepure tar from the resinous material contained in the mixture and finally isolating the bases from said resinous material by fractional distillation, substantially as described.

2. The process .of recovering resinous bases having a high boiling point from tar, which comprises distilling off the phenols, diluting it with coal tar, previously freed from phenols, removing the carbon by filtration, treating the product with a caustic solution, removing the lye, stirring the product with diluted sulfuric acid, removing the sulfates, cooling the mass, separating the pure tar from the resinous material contained in the mixture, extracting said resinous material with water to remove the soluble bases in the form of sulfates, treating the sulfate solutions with caustic alkali, and finally isolating the bases from the insoluble material thus produced by fractional distillation, substantially as described In testimony whereof I have aflixed my signature in presence of two witnesses.

ERNST WIRTH. [11. s.] Witnesses:

HELEN NUFER, ALBERT NUFER. 

